1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0-or-later
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun * Digital Audio (PCM) abstract layer
4*4882a593Smuzhiyun * Copyright (c) by Jaroslav Kysela <perex@perex.cz>
5*4882a593Smuzhiyun */
6*4882a593Smuzhiyun
7*4882a593Smuzhiyun #include <linux/time.h>
8*4882a593Smuzhiyun #include <linux/gcd.h>
9*4882a593Smuzhiyun #include <sound/core.h>
10*4882a593Smuzhiyun #include <sound/pcm.h>
11*4882a593Smuzhiyun #include <sound/timer.h>
12*4882a593Smuzhiyun
13*4882a593Smuzhiyun #include "pcm_local.h"
14*4882a593Smuzhiyun
15*4882a593Smuzhiyun /*
16*4882a593Smuzhiyun * Timer functions
17*4882a593Smuzhiyun */
18*4882a593Smuzhiyun
snd_pcm_timer_resolution_change(struct snd_pcm_substream * substream)19*4882a593Smuzhiyun void snd_pcm_timer_resolution_change(struct snd_pcm_substream *substream)
20*4882a593Smuzhiyun {
21*4882a593Smuzhiyun unsigned long rate, mult, fsize, l, post;
22*4882a593Smuzhiyun struct snd_pcm_runtime *runtime = substream->runtime;
23*4882a593Smuzhiyun
24*4882a593Smuzhiyun mult = 1000000000;
25*4882a593Smuzhiyun rate = runtime->rate;
26*4882a593Smuzhiyun if (snd_BUG_ON(!rate))
27*4882a593Smuzhiyun return;
28*4882a593Smuzhiyun l = gcd(mult, rate);
29*4882a593Smuzhiyun mult /= l;
30*4882a593Smuzhiyun rate /= l;
31*4882a593Smuzhiyun fsize = runtime->period_size;
32*4882a593Smuzhiyun if (snd_BUG_ON(!fsize))
33*4882a593Smuzhiyun return;
34*4882a593Smuzhiyun l = gcd(rate, fsize);
35*4882a593Smuzhiyun rate /= l;
36*4882a593Smuzhiyun fsize /= l;
37*4882a593Smuzhiyun post = 1;
38*4882a593Smuzhiyun while ((mult * fsize) / fsize != mult) {
39*4882a593Smuzhiyun mult /= 2;
40*4882a593Smuzhiyun post *= 2;
41*4882a593Smuzhiyun }
42*4882a593Smuzhiyun if (rate == 0) {
43*4882a593Smuzhiyun pcm_err(substream->pcm,
44*4882a593Smuzhiyun "pcm timer resolution out of range (rate = %u, period_size = %lu)\n",
45*4882a593Smuzhiyun runtime->rate, runtime->period_size);
46*4882a593Smuzhiyun runtime->timer_resolution = -1;
47*4882a593Smuzhiyun return;
48*4882a593Smuzhiyun }
49*4882a593Smuzhiyun runtime->timer_resolution = (mult * fsize / rate) * post;
50*4882a593Smuzhiyun }
51*4882a593Smuzhiyun
snd_pcm_timer_resolution(struct snd_timer * timer)52*4882a593Smuzhiyun static unsigned long snd_pcm_timer_resolution(struct snd_timer * timer)
53*4882a593Smuzhiyun {
54*4882a593Smuzhiyun struct snd_pcm_substream *substream;
55*4882a593Smuzhiyun
56*4882a593Smuzhiyun substream = timer->private_data;
57*4882a593Smuzhiyun return substream->runtime ? substream->runtime->timer_resolution : 0;
58*4882a593Smuzhiyun }
59*4882a593Smuzhiyun
snd_pcm_timer_start(struct snd_timer * timer)60*4882a593Smuzhiyun static int snd_pcm_timer_start(struct snd_timer * timer)
61*4882a593Smuzhiyun {
62*4882a593Smuzhiyun struct snd_pcm_substream *substream;
63*4882a593Smuzhiyun
64*4882a593Smuzhiyun substream = snd_timer_chip(timer);
65*4882a593Smuzhiyun substream->timer_running = 1;
66*4882a593Smuzhiyun return 0;
67*4882a593Smuzhiyun }
68*4882a593Smuzhiyun
snd_pcm_timer_stop(struct snd_timer * timer)69*4882a593Smuzhiyun static int snd_pcm_timer_stop(struct snd_timer * timer)
70*4882a593Smuzhiyun {
71*4882a593Smuzhiyun struct snd_pcm_substream *substream;
72*4882a593Smuzhiyun
73*4882a593Smuzhiyun substream = snd_timer_chip(timer);
74*4882a593Smuzhiyun substream->timer_running = 0;
75*4882a593Smuzhiyun return 0;
76*4882a593Smuzhiyun }
77*4882a593Smuzhiyun
78*4882a593Smuzhiyun static const struct snd_timer_hardware snd_pcm_timer =
79*4882a593Smuzhiyun {
80*4882a593Smuzhiyun .flags = SNDRV_TIMER_HW_AUTO | SNDRV_TIMER_HW_SLAVE,
81*4882a593Smuzhiyun .resolution = 0,
82*4882a593Smuzhiyun .ticks = 1,
83*4882a593Smuzhiyun .c_resolution = snd_pcm_timer_resolution,
84*4882a593Smuzhiyun .start = snd_pcm_timer_start,
85*4882a593Smuzhiyun .stop = snd_pcm_timer_stop,
86*4882a593Smuzhiyun };
87*4882a593Smuzhiyun
88*4882a593Smuzhiyun /*
89*4882a593Smuzhiyun * Init functions
90*4882a593Smuzhiyun */
91*4882a593Smuzhiyun
snd_pcm_timer_free(struct snd_timer * timer)92*4882a593Smuzhiyun static void snd_pcm_timer_free(struct snd_timer *timer)
93*4882a593Smuzhiyun {
94*4882a593Smuzhiyun struct snd_pcm_substream *substream = timer->private_data;
95*4882a593Smuzhiyun substream->timer = NULL;
96*4882a593Smuzhiyun }
97*4882a593Smuzhiyun
snd_pcm_timer_init(struct snd_pcm_substream * substream)98*4882a593Smuzhiyun void snd_pcm_timer_init(struct snd_pcm_substream *substream)
99*4882a593Smuzhiyun {
100*4882a593Smuzhiyun struct snd_timer_id tid;
101*4882a593Smuzhiyun struct snd_timer *timer;
102*4882a593Smuzhiyun
103*4882a593Smuzhiyun tid.dev_sclass = SNDRV_TIMER_SCLASS_NONE;
104*4882a593Smuzhiyun tid.dev_class = SNDRV_TIMER_CLASS_PCM;
105*4882a593Smuzhiyun tid.card = substream->pcm->card->number;
106*4882a593Smuzhiyun tid.device = substream->pcm->device;
107*4882a593Smuzhiyun tid.subdevice = (substream->number << 1) | (substream->stream & 1);
108*4882a593Smuzhiyun if (snd_timer_new(substream->pcm->card, "PCM", &tid, &timer) < 0)
109*4882a593Smuzhiyun return;
110*4882a593Smuzhiyun sprintf(timer->name, "PCM %s %i-%i-%i",
111*4882a593Smuzhiyun substream->stream == SNDRV_PCM_STREAM_CAPTURE ?
112*4882a593Smuzhiyun "capture" : "playback",
113*4882a593Smuzhiyun tid.card, tid.device, tid.subdevice);
114*4882a593Smuzhiyun timer->hw = snd_pcm_timer;
115*4882a593Smuzhiyun if (snd_device_register(timer->card, timer) < 0) {
116*4882a593Smuzhiyun snd_device_free(timer->card, timer);
117*4882a593Smuzhiyun return;
118*4882a593Smuzhiyun }
119*4882a593Smuzhiyun timer->private_data = substream;
120*4882a593Smuzhiyun timer->private_free = snd_pcm_timer_free;
121*4882a593Smuzhiyun substream->timer = timer;
122*4882a593Smuzhiyun }
123*4882a593Smuzhiyun
snd_pcm_timer_done(struct snd_pcm_substream * substream)124*4882a593Smuzhiyun void snd_pcm_timer_done(struct snd_pcm_substream *substream)
125*4882a593Smuzhiyun {
126*4882a593Smuzhiyun if (substream->timer) {
127*4882a593Smuzhiyun snd_device_free(substream->pcm->card, substream->timer);
128*4882a593Smuzhiyun substream->timer = NULL;
129*4882a593Smuzhiyun }
130*4882a593Smuzhiyun }
131